Oral-History:William E. Cory

About William E. Cory

William E. Cory is a 1971 IEEE Life Fellow "for contributions in the fields of electromagnetic compatibility and systems analysis," and a 1976 award recipient for contributions to the IEEE EMC Society. After high school study of mathematics and science in Dallas, Texas, Cory's naval service (1945-47) introduced him to advanced airborne radar techniques. Building on this background, Cory earned a 1950 electrical engineering degree at Texas A & M University.

As lead engineer for the U.S. Air Force Security Service, Cory became involved in the EMC field, performing classified Tempest research. In 1957, employed in the Advanced Weapons Development Group at Lockheed, Cory began work on Communications Navigation Identification problems. During his employment at the Southwest Research Institute, a research and development organization in Texas, Cory continued work on EMC. At Southwest Research, Cory mentored engineers who went on to play central roles in the EMC field.

This interview covers Cory's career, the development of the EMC field, and the development of the IEEE EMC Society. Cory assesses the roles of mathematics and physics in EMC, the influences of defense and industry on the field, and the significance of professional development. Cory defines methodologial devisions within the EMC field, providing a comparison between testing and computer modeling approaches. He describes the influences of EMC on standards, industrial design, and biomedicine.

About the Interview

WILLIAM E. CORY: An Interview Conducted by John Vardalas, IEEE History Center, 7 April 2006

Interview # 466 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.

Copyright Statement

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It is recommended that this oral history be cited as follows:

William E. Cory, an oral history conducted in 2006 by John Vardalas, IEEE History Center, Hoboken, NJ, USA.

Interview

Interview: William E. Cory

Interviewer: John Vardalas

Date: 7 April 2006

Place: San Antonio, TX

History of electromagnetic capability

Vardalas:

What are some of the key issues and questions that you want to address when talking about the history of electromagnetic compatibility (EMC) development as a discipline and as a society?

Cory:

Some of the key or critical items in the development of EMC technology included the original concept that this was a field dedicated to radio frequency interference (RFI) – in other words, a negative field. Eventually we realized that we should talk about electromagnetic compatibility and take a positive approach. The development of computer modeling technology as it applies to the EMC field is a key element now in getting an understanding of the technology that is involved in EMC. We have gone from simple testing technology to a computational technology with the viewpoint of resolving problems before they are encountered. The development of relationships with other countries and their requirements or standards has been a major factor. Our Society leadership took the position that we did want to develop with other nations. Consequently we encouraged the holding of international conferences in this field. We have seen dynamic growth in membership in our Society in China, India and other countries.

Vardalas:

When was it seen that EMC or electromagnetic interference (EMI) issues should be part of the actual design process? I gather that in the beginning it was reactive. What would you say in telling that story?

Cory:

That probably started back in the '70s when we realized that we could indeed develop methods for designing to meet the requirements of the EMC community instead of finding problems after designs had been completed and then trying to correct them. Therefore we embarked on some educational programs to try to get the circuit designers for example to consider the characteristics of electromagnetic interference and how to design equipment in a way that would minimize the problem from the start.

Vardalas:

Were they always willing to accept this?

Cory:

Practically never.

Vardalas:

That's what I figured. Another theme that came up in other interviews was the transition that was made from military funding to EMC being funded by the civilian or commercial sector. When, in your recollection, did this happen? Did you experience that in your own work?

Cory:

Yes. Back in the '50s the technical conferences that were held in those days in the United States were joint military-sponsored conferences. The Tri-Service conferences that were held at Illinois Institute of Technology called Conference on Ratio Frequency Interference was really heavily sponsored by the military. That slowly changed with the development of standards requiring companies to design their equipment to meet international EMC requirements. That forced the industrial companies to get much more involved.

Vardalas:

One theme I would like to bring up is your personal experiences with that process. Do you think those issues we have covered thus far are the big broad historical issues in development of EMC?

Cory:

I think so.

Vardalas:

What about the question of training engineers to be in this field? How did that develop? Was that a conscious thing? How was that done? To this day I don't know how that was done.

Cory:

It was done very poorly, in my opinion. There are only a few universities in the United States that specifically teach courses aimed at EMC technology. The University of Missouri at Rolla, Georgia Tech and a few others have courses in EMC technology, but most training occurs in the field when someone suddenly encounters a problem and discovers a need to find a way to solve the problem. Then they get personally involved and start looking at the literature and technology. To some extent they train themselves.

Vardalas:

Do companies today put an ad in an engineering journal saying, "I'm looking for a graduate in EMC engineering"? Can they do that?

Cory:

Twenty years ago that would not have occurred, but now there are people looking for EMC engineers.

Vardalas:

Can they get them out of universities or do they only learn on the job?

Cory:

A few come out of universities. Most of them learn on the job.

Vardalas:

That's interesting. In your experience, is this situation similar in other countries? Or do other countries have more systematic ways of doing things, for example in Europe or Japan?

Cory:

I think it is still somewhat universal. However, at the university in Beijing I know there is a research section for EMC and they are training some of their people to work in that field. That is also true in Atlanta at Georgia Tech. They have a research facility that is working in this field. They train a few people there to work in this field, but I don't think that is universally true.

Vardalas:

Given what is happening now with networking and its complexities, do you think that it is going to become a much more intense and important issue? Or do you think its role has stabilized now?

Cory:

I think it's pretty stable. The development of microelectronics has probably minimized some of the problems.

Vardalas:

Oh really? Would you briefly explain why that is the case?

Cory:

Electromagnetic interference occurs when large amounts of currents are changed, time varying fields, and the smaller the components and the less power they consume the less fields generated. There is closer coupling of any fields that are generated – which is still a problem, but it's not like it was back in the '40s and '50s when technology used relays heavily for example and ultimately developed vacuum tubes. All of those used a lot of current. Now properly designed microcircuits don't have as much of a problem.

Vardalas:

What about wireless interconnections? Is there a problem with compatibility if there are different devices operating through wireless exchanges all in the same room?

Cory:

There can be a problem if one or more of the devices has not been designed to meet EMC standards. To some extent I think that's a different kind of a problem. It's more a problem of frequency allocation. In the EMC field we worry about frequency allocation also, but it's not the main concern.

Vardalas:

I think it was Fischer who was telling me a funny story about what can be done with an automobile. Is that an area that is growing in importance? They are putting more electronics into automobiles now.

Cory:

It's a problem, but they understand that problem. There is a heavy commitment in the automotive industry to developing their products so that they are safe – primarily from external fields. However there was a time when if one keyed a transmitter in a HAM radio some cars could be stopped.

Childhood and education

Vardalas:

Let's go to the beginning now. You were born in Dallas. Right?

Cory:

Yes. I'm a Yankee. I was born in North Texas – in Dallas. That was Yankee country during the Civil War.

Vardalas:

Is that right?

Cory:

I like to say that. It shakes people up. I was somewhat of a chauvinist when I was young. In high school and pre-university I didn't think girls should be better at math and science than boys. Therefore I competed with one young lady through school. Consequently, I obtained a pretty good science and math background.

Vardalas:

You studied a lot of science in math in high school?

Cory:

Right. In those days in Texas we only had eleven years in high school, so I had to get 160 semester hours in college to get a bachelor's degree.

Vardalas:

What did you think of your high school education in Dallas?

Cory:

It was pretty good, though some of the courses were taught by people that were not professional those areas. At one time the basketball coach was the math instructor for example. We thought we knew more than some of our instructors then.

Vardalas:

I am fascinated in learning why people wind up in engineering. Do you recall when you first got interested in math and sciences and that whole area?

Cory:

That was probably in the 7th or 8th grade. In my case it was my chauvinist attitude. I couldn't let girls get ahead of me in those areas.

Vardalas:

Is that right?

Cory:

Yes. That's kind of a bad statement, but true.

Vardalas:

Did your parents encourage you? What were their backgrounds?

Cory:

My father was killed in a Ford plant explosion in Dallas when I was 4 years old, and my mother passed away when I was 10. I was shoved between all the aunts and uncles most of the summers and saw a lot of country cousins in relatively poor environments. Therefore I got a burning desire to do better.

Engineering education and naval service

Cory:

When I first started college I planned to become an agricultural engineer and I was going to be the savior of farming in the United States.

Vardalas:

What happened? Why didn't you stay with it?

Cory:

I got to be 18 years old, World War II was happening and I joined the Navy. I didn't know enough to fail the aptitude tests for things that did not interest me, so I just passed anything. Then they stuck me in Captain Eddy's Radar Tech school. I went to Wright Junior College to learn basic electrical engineering, then Gulfport, Mississippi to learn basic electronics, how to repair radios and so forth and ended up at Ward Island [Corpus Christi, Texas] in advanced airborne radar techniques. That's how I got into the electronics field. When I got out of the Navy, I had matured enough to realize that the money was in the medical field, so I started taking premed. I fell madly in love with a little girl and got married and suddenly decided I had better get busy. Therefore I went back to Texas A&M and became an electrical engineer.

Vardalas:

That was because of your electronics background in the Navy.

Cory:

Right.

Vardalas:

What were your experiences in learning radar? Do you recall your thoughts from those days? Obviously they threw you into it.

Cory:

It was interesting. In the pre-radar, which was basic electronics and electrical engineering, there was a lot of mathematics and science. I found that very interesting. The actual repair of radios and radars was a little bit less interesting.

Vardalas:

You were interested in the ideas – the mathematics and science and behind it all.

Cory:

Yes.

Vardalas:

Why did you choose Texas A&M? Was that because you are a Texan?

Cory:

Yes, and it is a land grant college. In those days it was relatively inexpensive to attend. We didn't have a whole lot of money, so it worked out that way.

Vardalas:

What do you recall of your engineering education at Texas A&M?

Cory:

At the time it was very heavily oriented toward the electric power industry. We had some instructors who were electronic-oriented, and I felt I knew just about as much as they did about it after going through the Navy – but I really didn't. They were very good instructors.

Vardalas:

Did you start at Texas A&M in 1946?

Cory:

I went there for one semester before I got in the war. That was in 1944-45 and I joined the Navy in '45. I went back in '47 and finished. By the way, in those days one could take as many semester hours as the grade point ratio would allow. I was taking 22 and 23 semester hours. Today 15 is considered a lot.

Vardalas:

Was there any mention in your training about the appearance of semiconductors at that stage?

Cory:

No. We were still all vacuum tubes pretty well. Right after that, in the late '40s or early '50s, was when the point junction type transistor first came out. When I started designing electronics after college, we were using only vacuum tubes.

Vardalas:

Did any of your professors or teachers have a strong influence on you or inspire you?

Cory:

There were a few, but the one I really think about was one at graduate school. His name was Dr. Fred Barnes. He wrote a lot of books in mathematics.

Vardalas:

Was this at UCLA?

Cory:

Yes. I was taking information theory type courses at UCLA. He really was an outstanding professor.

U.S. Air Force Security Service employment

Vardalas:

Like many engineers, your life seems interspersed between school and work going back and forth. Let me ask you about your first job. It says here USAF Security Service, San Antonio, Texas.

Cory:

I graduated in January of 1950. Probably only 10 percent of my graduating class got jobs in their fields.

Vardalas:

Really?

Cory:

It was pretty bad at the time. I got two offers. One was with an oil company in Houston and the other was with the Air Force Security Service in San Antonio in what called COMSEC Engineering. It was dealing with communications security equipment, encrypting equipment and things of that sort. That was really an interesting time. This organization was moved from Washington D.C. to San Antonio. I was put in a vacant room with a graduate of the University of Texas. Texas A&M and the University of Texas are rivals.

Vardalas:

Okay.

Cory:

This young man and I were both graduates, and we were put in this empty room and told to develop a lab to do research and development in the electronics field.

Vardalas:

They gave you quite a challenge.

Cory:

We sat down and ordered a whole bunch of nice equipment – which we never got. An old Master Sergeant took us over to a salvage area at Kelly Air Force Base and we scrounged equipment and got it all working and did our job.

Vardalas:

You say you never got what you ordered. No one was going to give you that equipment that you wanted. Is that what you are trying to say?

Cory:

The budgets were not there. We tore old equipment apart and got components and found test equipment and repaired it and so on.

Vardalas:

The mandate was to set up an R&D facility to do precisely what?

Cory:

To develop devices in the field of encrypting communications equipment – facsimile, television, voice, teletype, etc.

Vardalas:

Did you have access to anything that was being done by the organization that had become NSA and other organizations such as that? Or were you doing it on your own?

Cory:

We were the Air Force component responsible for that kind of thing, and we all worked very closely with the National Security Agency, which had the lead responsibility for the United States in those fields. We were concerned with making sure that whatever was developed met the requirements of the Air Force.

Vardalas:

I see. You were in touch with all of the other developments going on, and your job was to make sure that it fit the needs of the Air Force.

Cory:

Right.

Vardalas:

Do you recall what it was like? Was it straightforward? With two guys from competing universities working together, how did it all turn out?

Cory:

We did real well with one another, except during football season.

Vardalas:

I understand that. You continued in this field for some time. Is that correct?

Cory:

Yes. I was there for about seven years.

Vardalas:

I see you kept changing roles in that organization.

Cory:

Right. In effect it was the same job. It just got bigger and bigger and I was responsible for more than just myself after a while.

Vardalas:

I see you moved from teletype to voice systems.

Cory:

Right.

Vardalas:

Do you recall some of the challenges involved? It is not straightforward going from teletype to voice systems.

Cory:

Right. The main challenges were to do with understanding the principles of that particular technology. Teletype is relatively simple with an on-off keying kind of system whereas voice had multiple frequencies and different modulation characteristics than teletype. It was a matter of bandwidths and encoding principles and things of that sort.

Tempest

Vardalas:

Okay. Tell me about Tempest, since it is EMC. How did it start?

Cory:

That was the key element of my getting into the EMC field. In security we recognized that these fields that were being generated by equipments could be intercepted, and if someone were clever he or she could understand what was being processed.

Vardalas:

The signature.

Cory:

Right. The signature. This field was called Tempest. I had that particular responsibility for the Air Force. I was the lead engineer for Air Force Security Service. We had other groups at Wright Patterson and Rome Air Development Center for the Air Force working in this field too, and we all associated closely with the National Security Agency. When that developed I started thinking about things like, "Why are these fields generated? What can we do to mitigate them? Who is doing work in this field?" and things of that sort. That is what led me to the Tri-Service Conferences on Radio Frequency Interference. Out of that eventually grew a proposal to form a group within the IRE at the time. That was probably in 1957 or so.

Vardalas:

Were you working with Lockheed when that started?

Cory:

Yes. I had a friend that worked with me at Security Service that had left and gone with Lockheed, and he came by and tried to talk me into going out there. I filled out an application and they offered me a job without an interview. Then I told them I had to have more money and they agreed, so we went to California.

Vardalas:

Okay. Let's finish up on Tempest. I want to understand what Tempest was about. Was it in your purview to know which service started Tempest? Was it a Joint Services thing or did one service push it first? Was it an Air Force thing? How did Tempest come about?

Cory:

It came about primarily by the National Security Agency getting all the Services associated with COMSEC engineering together to talk about and start working on this problem. It was led by the National Security Agency.

Vardalas:

Was the object of Tempest to look at the various electromagnetic fields generated by equipment to get some kind of signature and identify what the equipment was doing? Was capturing that information the idea?

Cory:

That would be a positive viewpoint. The real problem was to eliminate those fields.

Vardalas:

So that no one could see them?

Cory:

Right. So it was a protection.

Vardalas:

To create a null field to basically null everything out.

Cory:

Right, or better to eliminate the fields.

Vardalas:

I see.

Cory:

Later on I spent a month in China lecturing on EMC. At one place they wanted me to give lectures on Tempest. I told them I could only tell them the unclassified stuff, and the funny thing is, they proceeded to tell me what they were doing in Tempest.

Vardalas:

How long ago was this?

Cory:

It was not too long ago. It was probably eight years ago.

EMC interference and the Air Force

Vardalas:

When I spoke to some of the other fellows involved in EMC, a lot of them seem to have been driven by naval platforms. These platforms had a lot of equipment generating all kinds of things all over the place – radar, fire control and everything was going on, whole ships, and they realized there was a problem. Were aircraft seen the same way? Did the Air Force see EMC interference issues as a problem when you were there?

Cory:

Yes. They had a number of problems. One was the mitigation of P-static from aircraft. Lightning protection is a big problem with aircraft. Then there was the problem of making sure that all the equipment on the aircraft work properly together. There were those three different kinds of problems, and different approaches are used in solving each.

Vardalas:

Did you encounter any problems about having more and more complex equipment operating together? Do you remember incidents where this was a problem?

Cory:

The goal of EMC is to develop each piece of equipment so that it will not interfere with or be interfered with by anything else. There is not only the radiated fields coupling, but the conductive fields on the power lines and communications lines. There were both conductive problems and radiation type problems.

Vardalas:

Was the Air Force encountering these problems in their planes back in the '50s? Do you recall?

Cory:

Not too much, because when aircraft is designed one hopefully gets the equipment working. I recall that I designed a navigation system at Lockheed that worked – until they bundled all the cables together nicely into conduits. Then they had interference problems.

Then we had to solve mutual coupling problems. When they originally put in the equipment and just laid the cables out without securely bundling them up, it worked really well.

Lockheed employment; graduate studies

Vardalas:

Did you start with Lockheed in '57?

Cory:

Yes.

Vardalas:

Between then you went back to graduate work at Trinity in San Antonio.

Cory:

Yes.

Vardalas:

You took economics/mathematics at Trinity from 1953-57. What possessed you to do that? I can understand your taking mathematics, but why economics?

Cory:

I had a burning desire to get a Ph.D., and in San Antonio they did not offer any. Therefore I had embarked on taking all the math courses so that if and when they offered a doctorate degree I would be prepared to work on my dissertation.

Vardalas:

Why economics? Did you want to go into management?

Cory:

That was a guise, because the graduate school didn't have mathematics as a curriculum. Economics was my curriculum.

Vardalas:

I see. That was the back door so to speak.

Cory:

I like economics however.

Mathematics and physics in EMC

Vardalas:

Something in your education parallels some of the fellows in EMC. I would like to bounce this idea off you and see what you think. It seems to me that those who were attracted to and went into EMC were interested in physics or mathematics more than the average engineer. They all offered theories about it. Why do you think? It seems to me that in order to tackle EMC one has to know more about fundamental processes. Is that true? Why do you all have that attraction to mathematics and physics in common?

Cory:

To really work in the EMC field one cannot be just a circuit designer. One must understand antennas and electromagnetic propagation as well as circuits and designing circuits. One has to have a broader viewpoint than many engineers. One cannot just specialize in one category. I think you will find that many EMC engineers have a broader background than many other types of engineers.

Vardalas:

In trying to analyze the problems in compatibility interference, is it true that it required more sophisticated analysis than just bench work?

Cory:

Originally it was simply a procedure of brute force solutions – filtering and shielding and things of that sort. Ultimately as the mathematics developed and computer technology developed faster and larger computers that could analyze larger matrices so that a system could be simulated.

Vardalas:

That was much later.

Cory:

Yes. That has probably developed over the last twenty years. It has gotten pretty good now, as I understand it.

Vardalas:

Almost everyone in the field of EMC that I have interviewed had a fascination with mathematics and physics. I am wondering what it is in the personalities. Is it a coincidence or does a person need physics and mathematics to work well in this area?

Cory:

To understand antennas and propagation one has to know a little bit about mathematics and physics.

Vardalas:

Did your university education do much antenna theory?

Cory:

No. I got more of that when I was in the Navy than I did in school.

Vardalas:

Okay. You learned it yourself actually then?

Cory:

Yes.

Vardalas:

Then you went back into physics again. You were interested in physics and you went to Trinity University again. In what part of physics were you interested when you did this graduate work in 1963-65? Do you recall?

Cory:

That was basically mathematics, not physics.

Vardalas:

You took mathematics courses again in 1963-65?

Cory:

Yes. They really did not have physics courses out there. I don't know why I wrote that on my CV.

Vardalas:

This was more advanced mathematics. You were still building up those courses, getting ready for that Ph.D.

Cory:

Yes, until I was made a research director at Southwest Research. Then I said to myself, "They're not paying me to go to school" and gave up on that.

Lockheed; Communications Navigation Identification problems

Vardalas:

Tempest was the first time you got drawn into EMC-related issues. Let's move on to Lockheed. You mentioned that this was when you got into the CNI problems.

From '52 to '57 I was in Air Force Security Service working in the Tempest field. When I went to Lockheed the position I had was in the Advanced Weapons Development Group, which was aimed at developing proposals for Lockheed Aircraft to solve particular problems. Based on my having been in Security Service, I was given what was called a CNI responsibility – Communications Navigation Identification problems.

Vardalas:

What were some of the things involved in CNI? I gather that basic navigation is one thing.

Cory:

Yes. Communications was pretty well fixed at that time and not really a major problem, but navigation was beginning to be a real problem. The development of inertial guidance systems, and gyroscopic systems were just coming along. One thing I worked on was an antisubmarine warfare aircraft. What that means is, it is based at some point in the United States, for example, it flies quite a way out to a station and goes into a search pattern. In theory if it finds a submarine it can go into hunt the identification and, possibly the kill pattern. There are three distinct kinds of navigation problems. At the time we didn't have good Loran systems and certainly didn't have satellite communication systems. Therefore navigation was a severe problem. I managed to get a team together. Litton had developed a gyroscope system that was small and airborne, Lyberscope had a small airborne computer system and Rand had a Doppler radar system. We also included a celestial package on it to limit system errors. I got a team to put all of this together, and it worked until they bundled everything together.

Vardalas:

Was EMC or EMI an issue about which Lockheed was consciously aware?

Cory:

Yes, but it was not a major thing. It was one of those things where if something didn't work the attitude was, "What's the problem? We'll fix it." It wasn't designed with that in mind.

Vardalas:

How did you find the problem with the cabling? Was it obvious or did people have to hunt around to find out why it was not working when they bundled the cables?

Cory:

I actually left before they solved that problem, but the way they solved was to separate some of the various cables so that interference is minimized.

Vardalas:

Did they realize where the interference was coming from as soon as it happened, or did it take time to figure out what was causing it?

Cory:

It became pretty obvious. It really is pretty obvious.

Vardalas:

Did you leave Lockheed or just the Burbank group?

Cory:

My boss at Lockheed was made a division head at Atlanta and wanted us to go with him. We agreed to go with him on the condition that if we really didn't like Atlanta we wouldn't stay long. We went to Lockheed-Marietta in Atlanta and kind of liked it there, but wanted to come back to Texas, so that's what we did.

Conferences on EMC and EMI

Vardalas:

I think it was Joseph Fisher who told me that at some point the companies, through the mediation of the military, started meeting to discuss EMI issues – engineers from Litton and Lockheed. Do you recall meeting with other companies to discuss EMC or EMI issues, especially when you were working together on a project? Does that ring a bell to you at all?

Cory:

I only remember those kinds of discussions at conferences. There were Joint Service Committees that met to discuss the overall problems, and a lot of companies would be invited to some of those sessions. It was going on before, but it probably didn't involve the companies until the late '60s or early '70s. Within the Services it was being discussed since the late '50s.

Vardalas:

I imagine there was a problem with security. Companies were invited in to learn of some of the issues, but how did this all work when some were working on secure problems and others were not? I'm wondering how much could be given away.

Cory:

In general we were very restrictive on the Tempest problem. It was, to a very large extent, restricted to the government groups. Eventually a few companies that did testing were cleared to help out in the test and evaluation areas.

Southwest Research Institute

Vardalas:

You went to the Southwest Research Institute. That was when you came back to Texas. What kind of organization is that?

Cory:

Let me explain that. When I was with the Air Force Security Service I developed a device to mitigate against Tempest problems and got some money and had a contract with Southwest Research to transistorize this device. I had done it using vacuum tubes. Southwest Research is a not-for-profit contract research and development organization. It's like a university but it is not a teaching university. It has engineers and scientists in most of the fields of engineering and science. It currently has about 3500 people in it and does about $600 million worth of contract research and development, about half for industry and half for governments, worldwide. Since I had that contract out there, they pursued me all the way to Lockheed and kept trying to get us to come work out there, so when we decided to come back to Texas I took a position with Southwest Research.

Vardalas:

Electromagnetic compatibility is one of the issues you have listed there. What was the EMC project or research agenda at Southwest and how did you set that up?

Cory:

When I first got there I was assigned to a project in nondestructive testing. I was working on using the Barkhausen effect to evaluate materials. It just happened to be a project they had. One pretty well worked on whatever they had. Because of my Tempest background I got a little group started and got some contracts in Tempest engineering and built up a group in that field at Southwest. Eventually it had twenty or so people in it. It's still going on a little bit. Like any engineer, I developed slowly. I started with my own little projects and got people working for me, and it got bigger and bigger. I eventually got to be a manager, then a director and eventually a vice president. All of these things that are listed on my CV are sort of interconnected by electronic systems. The bioengineering was oriented to medical instrumentation, geoscience was instrumentation-oriented and so on.

Vardalas:

Southwest Research contracted out to both government and industry. How was EMC being funded?

Cory:

It was funded primarily by the Air Force. Eventually it got to where we would do test and evaluation work for companies that were designing equipment that had to meet the requirements of the Tempest field. That broadened out into industrial electromagnetics, international standards and so forth.

EMC and design

Vardalas:

When do you recall EMC coming to be seen as an integral part of the process of design rather than just being brought in after things something goes wrong?

Cory:

A few of us in the EMC community started preaching that probably in the mid-'70s or so.

Vardalas:

That late?

Cory:

It was probably the early '70s. It's still not totally accepted everywhere. People are still designing equipment and then when they get to the test phase find out they have a problem, even though we have given them a tutorial course on how to design equipment to meet the standards. The typical engineer knows everything and doesn't need to consult anyone.

Vardalas:

What's the saying? "Don't even look at the manual."

Cory:

Right. I hate to say that about us, but we all think we know everything.

Vardalas:

Which of the industries were first most receptive to this? What sectors or companies do you recall? By size, by area of work or by product, which ones?

Cory:

Perhaps the automotive industry was more adaptable to the concept of designing to meet requirements from the beginning. Companies that were involved in international sales of their products really had to design their equipment properly. At one time the standards of some other countries were more restrictive than the U.S. standards. Now they are pretty well compatible across nations.

Vardalas:

I gather that the tradeoff is that it seems expensive at first to do the extra work because of EMC concerns, but that it saves money in the long run. Was that the economic argument you were trying sell to companies?

Cory:

Yes. When you design equipment and have it all in the pre-production model and suddenly find out you've got a problem, it is sometimes very difficult to redesign that equipment to solve the problem – relay out the circuit boards, add filtering here and there, add shielding here and there, whatever has to be done. It is a lot more economical to consider it from the start.

Vardalas:

I gather too that there is a challenge between what each engineering group thinks is the best way to design a product. The story that Mr. Fischer gave me was about naval architects designing a ship. They want to worry about the center of gravity in where to put things, but they really messed up everything else. After the fact, the incompatibility problems were such that they had to tear it apart and redesign the whole thing. Did you encounter this kind of thing?

Cory:

Not as much as the people who were designing shipboard systems. The naval architecture just considers it a big platform and they don't give a hang about what you put on it or where you put it.

Vardalas:

There is the reluctance when someone is designing something. They have their own needs to solve and then here you come along telling them they need to do this too. Was there initially a lot of resistance from groups you worked with when you told them this or was it something where they all agreed, "Yes, we should be doing this"?

Cory:

I guess it came about because people just ignored it altogether. They designed a system to function properly, but they didn't consider that they had to meet these standards. I don't think there was reluctance so much as there was an ignorance – ignore the problem.

Vardalas:

I see.

Cory:

A lack of awareness even though they have been told.

EMC standards

Vardalas:

Tell me about EMC standards. How easy were they to put down? I'm sure a lot of people don't like standards that conflict with what they want to do.

Cory:

Yes, particularly when you try to standardize the standards between countries. Every country has its own idea. Originally trade barriers were encountered because standards were erected to protect their equipment.

Vardalas:

Non-tariff trade barriers.

Cory:

Yes, things of that sort. Those have slowly been resolved.

Comparison of military and industrial standards

Vardalas:

What about within the United States? Was getting standards a straightforward thing with everyone agreeing on the standards or were there different camps?

Cory:

There were camps to some extent. The military people had a little different camp than the viewpoints of the industrial people, but eventually those were resolved.

Vardalas:

What separated those camps? What were the key issues that divided these camps? Precision? Costs?

Cory:

I guess it was just history. The military developed their standards their way and industry developed a different way and each had their own prerogatives.

Vardalas:

Okay. As simple as that.

Cory:

Yes, I think that was the major problem.

Vardalas:

I would imagine military standards would be more rigorous than individual standards. Or were they just a different set of standards?

Cory:

They were a little different in setting the limits, in describing specific testing techniques and in the recognition of what meeting particular tests meant. I talk about real world situations. The military has a specific test and that's not necessarily a real world situation; it's an artificial environment relative to the real world.

Vardalas:

Do you mean extremely artificial?

Cory:

For example, in evaluating the signals that are coupled from a device onto the power line. They create what is called an artificial network – a line stabilization network (LSIN). That is an artificial network to determine the magnitude of the fields. It has a certain impedance, and depending on the impedance characteristics of the source of the emanation there will be either a big or little signal across that artificial environment. That is supposed to simulate the real world power line, but it does not.

Vardalas:

Aha. What does the real world approach do?

Cory:

In the real world I can prove that the magnitude of the signal coupled to the power line can vary by plus or minus 30 dB from what is measured across the LSIN. It is a standard technique that everyone can use and it is something to which they can test. In the real world however it may or may not yield equipment that will work with some other equipment.

EMC modeling

Vardalas:

I see. How does that integrate into the fact that you are telling me that the EMC field became more oriented to computer modeling in order to simulate testing? It seems to me that there you are doing simulations again. Is that real world or not?

Cory:

In the modeling area you would try to model the power line.

Vardalas:

Is it really real world? Is the whole system simulated, and is simulation done to save money? Is it cheaper than testing?

It is supposedly cheaper than designing and then testing if you can model initially. There is a big group of people that do modeling relative to the EMC field. The problem is in several pieces. First, to model the electronics within a system and the physical placement of the parts and the magnitudes of the signals and how they might couple one to another through the power system and through the communications system within it. That's a distinct area in modeling: how to design equipment so that it works properly. Then the next problem is to determine what kind of signals come out of this device and how those signals couple to another device. The question then is how the other device reacts to those signals. All of that requires something in between there that might be called the real world – whether it's a power line, an electromagnetic coupling through the air or what. The real problem is that for example we all consider that propagation is a characteristic of free space. All the equations we use are oriented to free space to some extent, and antennas are somewhat idealized. It has become a real challenge to get the correct answer with all these modeling programs.

Vardalas:

I gather you are saying that the first is modeling of one component and modeling many different components internally and then modeling their coupling through a medium that connects them somehow – which is not the vacuum but air and objects and whatever.

Cory:

Right.

Vardalas:

How successful has modeling been?

Cory:

I don't really know the answer to that. The people who do the modeling claim they are quite successful, and I frankly don't know.

Vardalas:

I imagine this is very computationally intense and is quite sophisticated.

Cory:

Yes. It requires a large matrix analysis kind of program.

Vardalas:

Very much oriented to matrix analysis.

Cory:

Yes.

Vardalas:

I see. Are there those in the profession who specialize in the modeling versus those that don't specialize in the modeling?

Cory:

Right.

Vardalas:

Who employs whom? Where do people in your field find your niches in the world?

Cory:

We all come together at the EMC Society meetings, and I think the modeling people are university-oriented people and the test and evaluation people are the industry-oriented people – to a large extent but not totally.

Vardalas:

How much real communication is there between the two?

Cory:

Not a lot. We come to the same meetings where we each have sessions and don’t necessarily go to each other's sessions.

Vardalas:

I gather it would be beneficial if there were better communication and a good exchange of ideas.

Cory:

There is probably more exchange to the modeling people than vice versa, because the modeling people have to get down to the component level in their modeling whereas the guy that is doing the designing does not particularly care about the modeling piece.

Vardalas:

In principle the modeling people are saying it will save time and money to do more modeling.

Cory:

Yes. If it could be done. The degree of complexity and skill levels in the modeling are totally different from that in the electronic design levels.

Vardalas:

And you are all members of the same Society?

Cory:

Yes, although the modeling people may be heavily oriented toward the antennas and propagation field or Computer Society. I don't want to say they slop over into EMC, but they are cross-training into the EMC field.

Vardalas:

You mention that modeling is university-oriented. Do they have enough hands-on practical understanding of the things they are trying to model versus the abstract idea? Sometimes knowing something concretely makes a big difference. Do you see that at all?

Cory:

Yes. I retired sixteen years ago, but I stayed in the EMC field and did consulting up to a couple of years ago when I totally quit. The man that is doing the modeling is forced to understand the characteristics of the electronic circuits in order to put the data into his system. He may not care how it actually works, but he has to understand the parts and pieces.

Vardalas:

That is understanding the parts and pieces as far as they can be quantified and put on paper, but is it the case from your experience that when you design a system that besides what is on the specs there is a lot of tweaking that goes on I would imagine. There are things that cannot be gleaned just from looking at the specs. Right? Is that something that is important in the modeling that is being left out?

Cory:

They pretty well have to put in the electrical characteristics of the components and the physical layout of the components to do a good job of modeling.

EMC in biomedicine; electromagnetic field safety

Vardalas:

With more and more biomedical devices running electronically and multiple devices in intensive care units and all these things, how important has EMC been in the biomedical field?

Cory:

There are several aspects of that. One of course is the aspect of making all the equipment work properly, and that's important. The second field is the problem of the bioelectromagnetic effects area and how these electric fields influence the body. There are beneficial effects and there are detrimental effects, so there is a big field of study in bioelectromagnetics. There is a separate Society for that, but it calls heavily upon the people in electromagnetic propagation and electromagnetic interference to work with the medical people. The bioelectromagnetics effect, starting 20 to 25 years ago was not too well understood, and to some extent it's not totally understood today. How an electromagnetic field will affect a biological cell for instance.

Vardalas:

In a sense that is a very broad view of EMC, because it's a biological system. It's a compatibility issue, but in a more sophisticated way.

Cory:

Right. From an EMC engineer viewpoint it covers anything that generates electricity or electromagnetic fields and anything that considers the coupling between them, such as radio and television. Anything that uses electric energy is considered. It doesn't matter whether using it is causing good effects or bad effects.

Vardalas:

Or whether or not it is biological.

Cory:

Right.

Vardalas:

That explains all these papers on the effects of high-intensity 60-Hz electric fields. I gather all these various examples have to do with high-voltage transmission lines.

Cory:

Yes. Southwest Research has a fellow or sister organization that used a baboon colony as experimental animals for medical research. Baboons have a large lung and heart somewhat similar to man, and the question was what behavioral and physiological effects occur from their being under power lines.

Vardalas:

Right.

Cory:

There were big studies that looked at communities where the apparent incidence of cancer was higher than surrounding areas and trying to discern what was the reason for this. One of the things they thought it pointed to was an association with high power lines and distribution systems. There may have been other factors too. A worldwide study in that field of bioelectromagnetics started some 20 or 25 years ago, and this program was just a piece of that.

Vardalas:

Who was funding all of that?

Cory:

This was under the Environmental Protection Agency (EPA) for the U.S.

Vardalas:

It was not the public utilities that were funding it.

Cory:

For the U.S. it was the EPA. Our program was a joint program between the EPA and the Japanese Central Research Institute for the Electric Power Industry (CRIEPI).

Vardalas:

This was at least 20 years ago and this is still a hot topic. What is your thinking on this whole debate about the safety of high power lines from the experience you have had? Are there still questions to be answered?

Cory:

What is the objective of a research group? Is it to answer a question finally or is it to get another grant? Our study showed that there are some transitory effects when an animal is placed in a high-intensity electric field. A group of baboons for example tends to huddle. What are they doing? They are mitigating the magnitude of field they are experiencing.

Vardalas:

Are they?

Cory:

Yes. If you stand straight up you are encountering a large electric field, whereas if you drop down low it's a smaller electric field. They were actually reducing the amount of the field by reducing their height.

Vardalas:

They really did this instinctively? How did they know?

Cory:

I don't know how they knew to do that, but they did.

Vardalas:

If the field turned off they would not do that and if it was turned on they would do that?

Cory:

Initially. Then they got used to it and ignored it.

Vardalas:

What were the effects on them in the end?

Cory:

We didn't find any physiological effects.

Vardalas:

Did the intensity of the field vary? Was it 500,000-volt transmission or 700,000-volt transmission?

Cory:

It was a field test with an electric field of about 60,000 volts per meter and some associated magnetic fields. We created a test environment that would simulate that.

Vardalas:

I know there are some places where 700,000 volts are being transmitted. Was that the kind of intensity being studied?

Cory:

You have to figure out what the actual field levels are at the ground, and they are not 700,000 volts per meter.

Vardalas:

Right.

Cory:

The fields we generated were considered excessive – deliberately.

Vardalas:

That is interesting about the baboons huddling like that. I noticed a whole bunch of these papers in your CV. All of these were a result of this big international project. Does this same kind of issue appear with cell phones and people using them?

Cory:

Yes. There is a lot of debate as to whether or not there is a cell phone problem when one gets the transmitters right up by the ear or the eye. Those fields have been measured. We are concerned about the safety of field at all frequencies – not just the power line frequencies. What level is safe? How many milliwats per cubic centimeter are allowed to be safe? Is it a heating effect only, like a microwave oven, or is there some other effect? Is it electric fields across a cell that causes a problem? Or is it the rate of change of the field (electric or magnetic)?

Vardalas:

Neurological problems?

Cory:

Right. Or what. There is all that kind of experiment going on still today I think.

There is the Technology and Society. Somehow I thought you were involved.

Cory:

You mean one of the IEEE board committees?

Vardalas:

Yes.

Cory:

Yes.

Vardalas:

In discussing the questions of technology and society, was the question of health effects of electromagnetic couplings discussed?

Cory:

That committee really didn't go into those kinds of details, but looked more at the interplay between technology and society.

Biomedical device compatibility

Vardalas:

Let's go back to biomedical for a minute. Besides the effect of electromagnetic coupling to biological organisms and how it can affect them, what about the interconnection of a coupling of devices in a hospital? Medicine is based more and more in electronics with lots of devices all over the place. How much work is done in that and did it evolve as an important area to think about in the EMC field? I have a follow-up question for that as well. When there is a question of compatibility and a problem of not having compatibility, it seems to me there would also be liability issues. Starting with biomedical, does someone sign off on these? Does someone become liable? How does this all work? Let's start with what the technical issues are now in biomedicine about EMC in general.

Cory:

In general the biomedical instrumentation has to meet all the requirements or standards that we are talking about. If that is done, then the fields that are generated and the coupling to power lines are small enough that there are no problems of inoperability within the hospital. However many hospitals have signs, "Turn off your cell phone." Cell phones can cause problems to some of these equipments.

Vardalas:

When the transmitter is close enough to the equipment?

Cory:

Right. Liability? I don't know how that would enter into this.

Vardalas:

If something fails and it's a compatibility issue. Are these standards so precisely understood that there is no room for error saying that maybe somewhere down the line some kind of complexity will be introduced that would raise incompatibility issues and still meet the standards?

Cory:

The equipment may all meet the standards. I'll give you an example of what happens. In Houston there was a case where somebody had all the telephone equipment on the top floor of a building, and suddenly it was found out that these things were not all working together. Primarily the problem was inadequate grounding. The equipment was put into a shielded enclosure up on top of the building there is a long ground line. And what is that? That is a top-loaded antenna. Instead of not radiating, all of a sudden it is radiating. All kinds of physical problems occur even though everything meets a standard.

Vardalas:

That is over and above the standards. It is just something that has to be understood.

Cory:

Right. There is no liability on the part of the equipment manufacturers. It's just inadequate design from the engineering viewpoint.

Vardalas:

I see. That is something that cannot be set in the standards, but one learns a proper way of designing things.

Cory:

Right.

Vardalas:

Do many biomedical equipment manufacturers get together and discuss these issues?

Cory:

EMC engineers are part of the community and of course they talk about these kinds of problems.

Vardalas:

How much of the EMC Society's membership deal with biomedical devices? Is that an important area for many EMC people, or do most tend to flit around from one thing to another?

Cory:

Yes. I doubt seriously that most people concentrate on one thing. The people that manufacture pacers at one time had some serious problems with magnetic fields because of the design of their equipment. They don't have that problem anymore.

Vardalas:

Today everybody has various screening devices. I would imagine they have to make sure that those don't set off pacemakers and things like that.

Cory:

Right.

EMC Society

Vardalas:

Just in general, what is your impression about how the Society has evolved? Has it grown to the expectations that people have held for it? What are your comments on the Society as an institution?

Cory:

Over the past 50 years or so it has gone from relatively few people to a large group of people working worldwide with international conferences and exchange of information. In my opinion the technology has developed and is developing very well. I don't quite know quite where it is going from here, but as it gets into nanotechnology and things like that there will probably be slightly different problems than with large devices.

Vardalas:

Has the Society met the needs of its members? What do you think of the EMC Society as an organization?

Cory:

I don't know how the organizations can do much more than be a forum for people to get together and exchange information. Peer-reviewed publications are a benefit from Societies, but the Society is not a means in itself; it is something in which individuals participate because they want to exchange information, in my opinion.

Vardalas:

Does the Society or IEEE actively go out to educate people about the need for more EMC? You mentioned the case of the communication center with a wire going down. This idea of increasing awareness of the importance of EMC.

Cory:

Only through presentation of papers at meetings.

Vardalas:

At these meetings are EMC people coming to speak to other EMC people. Do you see a need to get this message out to the wider technical community, or is that not an issue? You are talking to the converted at these EMC meetings. Is there a need to reach out further?

Cory:

The way that it is done is that the EMC engineer working within a company educates people within the company of the problems and solutions. It is kind of from the bottom up or something. That EMC engineer had either encountered a problem or been assigned the responsibility of insuring they meet EMC requirement. He/she searched the literature, attended EMC meeting to educate themself.

Conference papers

Vardalas:

You gave a keynote address in China in 1990. The title was, "Electromagnetic Compatibility Today and Tomorrow." Do you remember the key themes you brought out in that paper?

Cory:

At that particular presentation I tried to show what I considered the lack of real world testing for EMC because of artificial testing. I gave the LSIN issue and discussed making measurements in shielded enclosures, and then went into various developments in technology and how they might impact us at the time. Chaos theory was beginning to have an impact, and I talked about how that might apply to the modeling technique. Those kinds of things. I really just gave a status report of where we were and the kinds of things one ought to be thinking about, such as the impact of microelectronics on the EMC community, the need for improved multinational standards, and that kind of thing.

Vardalas:

You gave another in China in 1992 at the International Symposium on EMC. Then you went back to the low-frequency electric and magnetic field primate studies. That was eight years after they had been done. Why did you feel the need to bring this up to the Chinese?

Cory:

I guess because they asked me. I don't know why else I would have done that so late in the game.

Vardalas:

They must have asked you. Are they also now facing the same problem?

Cory:

It was sort of a status report I guess.

Vardalas:

Okay. In August 1998 in Denver you gave a paper, "Tri-Plate Test Facility." What is that? Is that related to EMC or is it something else?

Cory:

It is an EMC testing procedure – how to simulate electric and magnetic fields.

Vardalas:

On the surface that sounds like an easy question, but I guess it's not.

Cory:

It is a matter of just creating a big loop and putting things inside the loop or what. The tri-plate is a way to create a relatively uniform electric field. It uses basically three parallel plates, and the center one could be called ground and the other two are driven. This lets one work within the center plate and the upper or lower in a reasonably uniform field.

Vardalas:

You are worried about boundary effects in the center of this thing?

Cory:

Yes. There are boundary effects. Looking at the electric fields, in the center they are pretty well vertical and out toward the edge they start going other ways.

Vardalas:

What caused you to come up with this? Was there a need?

Cory:

Within the automotive industry the tri-plate testing method was being used, and our work was to quantify the characteristics of these things. At what frequency range could they be used? Where do they become resonant and create non-uniform fields?

Vardalas:

I see.

Cory:

And what happens when you put a conducting material within the plate and that kind of thing. That's part of what that study is about.

Vardalas:

What is the conclusion? Can these things work properly?

Cory:

Pretty well, but again, it's an artificial environment. These techniques create a standard procedure by which one item can be evaluated in different parts of the United States and get comparable answers. That does not necessarily mean the answers are realistic, but we don't admit that.

Consulting work

Vardalas:

Are you still a consultant?

Cory:

I was up until about two years ago.

Vardalas:

Was Cory Consulting mostly to consult people on EMC-related issues?

Cory:

Yes. I had some contracts with Japanese companies and when Southwest Research needed help I ran some projects for them. Things of that sort.

Career highlights; professional development and mentorship

Vardalas:

Thinking back over your career, which was quite long, of what are you most proud? Do you ever think about your past accomplishments? Or is that an unfair question to put to you?

Cory:

Some of the things that I contributed to the Tempest field in the early days – which were classified – were good accomplishments that pushed that field in certain directions. When I was going to school I had the idea that I was going to be an engineer. Now why would an engineer have to take all these courses in English, writing and literature? I was not going to do any of that. What would I become as my career developed? Well, I had to write reports. Later on I had to read and edit reports. I became a technical editor to some extent. Anyway, the thing for which I am probably most proud is my contribution I made in the development of people who worked for me.

Vardalas:

Tell me about it. In what way? That is quite an accomplishment. Of what are you thinking specifically when you say that?

Cory:

Young people that came along whom we taught about the EMC field and who became managers in the field and wrote papers in the field. Ed (Edwin L.) Bronaugh essentially got into that field while working for me at Southwest Research. I believe he is still on the Standards Committee of EMC.

Vardalas:

You are talking about your role as a mentor then.

Cory:

Right.

Vardalas:

Did anyone play that role to you when you were an engineer?

Cory:

The man I worked for at Southwest Research did that for me to a large extent. Prior to that, in the Security Service, I didn't really have any mentors. I was one of the only engineers they had in that particular field at Air Force Security Service. Most of the people in that group had developed through experience and did not have degrees. The chief engineer for the whole group was a history major – but he really was a fine engineer, surprisingly enough. It's kind of interesting how people develop outside their so-called career fields.

Vardalas:

You were pretty well left to your own devices in those early days.

Cory:

In the early days, yes – other than my coworkers, that one engineer I mentioned and a few military people that were really good about working to help us solve our problems.

Vardalas:

Did you ever feel that you were over your head when you were working by yourself? In the early days did you ever feel, "What have I gotten myself into?" or wonder what they expected from you?

Cory:

To some extent, but that's when I would get out the books and look at the literature and go talk to people and try to figure out the requirements.

In San Antonio the opportunities for professional development were not really great in those early days. They are much better now. The University of Texas at San Antonio has developed quite well, and Trinity has some good courses, but back then generally students were on their own to develop their professional careers.

Vardalas:

Your comment about when you were a student wanting to be an engineer and wondering what good English courses were to you caused me to think of another question. Looking back, after all you have been through, do you think engineers could use a broader training? Do you think that knowing more about society and other things would be useful to engineers? And if so, are they meeting that challenge?

Cory:

Yes. The difficulty is that within the engineering profession there is really so much to learn that there is just not a lot of time to devote to all the things that one will probably need later in one's career. Therefore one must continue learning throughout one's professional career.

Vardalas:

Is there any way of institutionalizing that informal process of learning? You mentioned earlier about professional development. Is there a way that IEEE could help engineers broaden their education?

Cory:

I don't know how IEEE could help. Somehow it has got to be an integral part of the education process to make sure that young people understand that they need a little bit broader education and that hundred percent dedication to electromagnetic field theory, for example, is not going to cut it. One has got to have a little bit broader perspective.

Vardalas:

I came across one senior executive who was an engineer who made the remark – and I don't know if this is true – that in the past engineers always rose to senior management within companies, but that now engineers cannot be found who have the necessary background and skills to rise up because they are so focused on narrow specialties. At the same time I pointed out to him that, "When companies hire they only want specialists." What is your thinking about this?

Cory:

I'll give Southwest Research as an example. We have two career fields at Southwest Research. Everyone starts at the technical level. One can develop strictly in the technical field all the way up to the department director level. One can slowly branch off and accept more management responsibilities and end up at the director level and vice president level. We recognize that highly skilled technical people are a necessity as well as people with good managerial capabilities.

Vardalas:

Yes, of course.

Cory:

To some extent the manager level is more about how one can deal with and influence people. Not a lot of people can do that well. Some people are just not good at that. They do an excellent job technically but just can't manage people.

Vardalas:

Okay.

Cory:

Unfortunately, nobody teaches that in the engineering field. One has to learn that later on as one develops toward that goal. Unfortunately our educational system does not teach us much, if anything, about one of our most important jobs. That of being a good parent.